[PATCH] tpm: turn on TPM on suspend for TPM 1.x

[Domenico Andreoli]

On Fri, Mar 22, 2019 at 12:51:20PM +0200, Jarkko Sakkinen wrote:
> tpm_chip_start/stop() should be also called for TPM 1.x devices on
> suspend. Add that functionality back. Do not lock the chip because
> it is unnecessary as there are no multiple threads using it when
> doing the suspend.
> 
> Fixes: a3fbfae82b4c ("tpm: take TPM chip power gating out of tpm_transmit()")
> Reported-by: Paul Zimmerman <pauldzim at gmail.com>
> Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen at linux.intel.com>
> ---
>  drivers/char/tpm/tpm-interface.c | 14 ++++++--------
>  1 file changed, 6 insertions(+), 8 deletions(-)
> 
> diff --git a/drivers/char/tpm/tpm-interface.c b/drivers/char/tpm/tpm-interface.c
> index 83ece5639f86..ae1030c9b086 100644
> --- a/drivers/char/tpm/tpm-interface.c
> +++ b/drivers/char/tpm/tpm-interface.c
> @@ -402,15 +402,13 @@ int tpm_pm_suspend(struct device *dev)
>  	if (chip->flags & TPM_CHIP_FLAG_ALWAYS_POWERED)
>  		return 0;
>  
> -	if (chip->flags & TPM_CHIP_FLAG_TPM2) {
> -		mutex_lock(&chip->tpm_mutex);
> -		if (!tpm_chip_start(chip)) {
> +	if (!tpm_chip_start(chip)) {
> +		if (chip->flags & TPM_CHIP_FLAG_TPM2)
>  			tpm2_shutdown(chip, TPM2_SU_STATE);
> -			tpm_chip_stop(chip);
> -		}
> -		mutex_unlock(&chip->tpm_mutex);
> -	} else {
> -		rc = tpm1_pm_suspend(chip, tpm_suspend_pcr);
> +		else
> +			rc = tpm1_pm_suspend(chip, tpm_suspend_pcr);
> +
> +		tpm_chip_stop(chip);
>  	}
>  
>  	return rc;

Tested-by: Domenico Andreoli <domenico.andreoli at linux.com>

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